不同应力水平砂岩颗粒料湿化变形试验研究

Experimental Study of Wetting Deformation of Sandstone Particle Material under Different Stress Levels

鉴于颗粒料湿化变形是土石坝、地基基础等工程中变形控制所考虑的重要影响因素,利用外置湿化水头的侧限压缩固结仪,对砂岩颗粒料进行了不同应力水平的湿化试验,研究了单线法湿化变形量与湿化应力、湿化时间的关系;对比了单双线法压缩固结曲线差异,总结了砂岩颗粒料湿化变形规律。试验结果表明,单双线法所测相对湿化变形随湿化应力的变化曲线均呈指数函数关系,此规律在湿化应力较低时吻合程度较高,在湿化应力较高时双线法比单线法所测湿化变形离散性大;所测相对湿化变形差值随湿化应力增大而有减小,最大差值为湿化应力0.10 MPa时的33.63%。单线法所得砂岩颗粒料湿化变形随湿化应力增大而增大,浸水时间相同时应力水平越高,湿化变形越大;随浸水时间增加,颗粒料湿化变形速率先增加后急剧减小,直至趋于稳定。

Wetting deformation is considered as an important influencing factor to control project deformation,such as earth and rockfill dam,foundation engineering.Confined compression consolidation apparatus with external wetting head was used to do wetting deformation tests of sandstone particle material under different stress levels.Relationship of wetting deformation and its influencing factors,wetting stress and wetting time was studied.The difference of consolidation curves between single-line and double-line methods was compared.And the wetting deformation regularity of sandstone particle material was summarized.The results show that change curves of relative wetting deformation with wetting stresses present the trend of exponential function by two methods.The matching degree of that trend is high in the low wetting stresses.Compared with the results of single-line method,the relative wetting deformation of double-line method appears large discreteness.In addition,the difference of relative wetting deformation decreases with wetting stresses increase,and the maximum is 33.63% when the wetting stress is 0.1MPa.For single-line method,sandstone particle material wetting deformation increases along with wetting stresses increases,and it also increases with stress level getting higher when it is in the same immersion time.With the immersion time prolonging,the rate of sandstone particle material wetting deformation increases firstly,then reduces sharply until trending to a stable.